You may have read in the news about a rare but troubling potential side effect from the COVID-19 vaccines. In late June 2021, the CDC reported that more than 1,200 Americans experienced heart issues potentially linked to the mRNA vaccines made by Pfizer-BioNTech and Moderna.
The two heart problems detailed in the report are myocarditis, an inflammation of the middle layer of the heart muscle, and pericarditis, an inflammation of the lining around the heart.
Michelle Johnson, a cardiologist at Memorial Sloan Kettering. says that these heart issues are very rare, treatable, and not as dangerous as COVID-19 itself.
Heart Inflammation Caused by COVID-19 Vaccines Is Rare
As of July 7, 2021, over 180 million Americans have received at least one COVID-19 vaccine dosage, and the CDC is continually monitoring data to make sure the vaccines are safe.
Heart inflammation has emerged as a potential problem, and CDC researchers are taking a closer look. This is another indication of how carefully vaccine safety is being monitored. Here’s what we know, based on data reported by the CDC on June 23, 2021.
- These heart problems showed up more commonly after the second dose.
- More men were affected than women.
- A large portion of cases (about 500 of 1,200) were in people younger than 30.
- Symptoms usually appeared within the first four days after a COVID-19 vaccine dose.
- Overall, for every million second vaccine doses administered, there were 12.6 cases of heart inflammation.
“This means that myocarditis or pericarditis after a COVID-19 vaccine is extremely rare,” says Dr. Johnson.
Myocarditis and Pericarditis Are Usually Treatable
In general, myocarditis and pericarditis are rare diseases and occur in less than 200,000 Americans per year, but either condition can be managed and successfully treated by a heart specialist.
“In most cases, both myocarditis and pericarditis will clear up on its own or will require medication,” Dr. Johnson says. “In severe cases, a patient may need to be hospitalized for a more aggressive treatment strategy — intravenous drugs, a device to help their heart pump blood, or surgery.”
When a case of heart inflammation did appear after COVID-19 vaccination, the CDC found that most patients were able to rest and recover quickly after treatment. People most commonly experienced fatigue, chest pain, and feelings of a fast beating, pounding, or fluttering heartbeat. According to CDC researchers, of about 300 people who developed the condition and were hospitalized, 79% recovered completely.
“It is good news the COVID-19 vaccines aren’t causing severe heart issues,” Dr. Johnson says. “These cases have been mild, and we have a number of good strategies to help patients like this.”Back to top
COVID-19 Itself Is More Dangerous than Side Effects from the Vaccine
In young people, heart problems are often caused by viral infections, says Dr. Johnson. It’s well understood that COVID-19 can cause heart problems in children — by itself or as a result of multisystem inflammatory syndrome in children (MIS-C).
“A young person is much more likely to get myocarditis or pericarditis from COVID-19 itself than they would from a COVID-19 vaccine.”
All three COVID-19 vaccines are safe and provide strong protection against severe disease, hospitalization, and death from COVID-19. Severe safety issues — including myocarditis, pericarditis, anaphylaxis (severe allergic reaction), and thrombosis with thrombocytopenia syndrome (blood clots with low platelets) — are very rare. The CDC continues to monitor these and all potential safety problems.
“We know that the benefits of the vaccine strongly outweigh the risks,” Dr. Johnson says. “I strongly recommend — and the CDC recommends — that everyone over age 12 get vaccinated as soon as possible.
July 12, 2021